TS 


-NRLF 


On  the  Making 
of  Silk  Purses 
from  Sows'  Ears 


On  the  Making 
of  Silk  Purses 
from  Sows'  Ears 


Contribution  to 
Philosophy 


Arthur  D.  Little,  Inc. 

n 

Chemists  .  Engineers  .  ^Managers 

Cambridge,  Massachusetts 

1921 


On  the  Making  of  Silk 
Purses  from  Sows'  Ears 


"You  Can't  Make  a  Silk  Purse 
of  a  Sow's  Ear  " 

EVER  since  somebody  said  it  first  — 
and  that  was  centuries  ago  —  it  has 
been  repeated  with  gusto.  It  has 
been  quoted  principally  for  purposes  of  dis- 
couragement. Whosoever  has  striven  for 
betterment,  to  make  something  desired  out 
of  that  which  is  held  in  low  esteem,  has  had 
to  feel  the  cutting  edge  of  this  hoary  old  saw. 
It  has  been  bothering  us  for  all  the  years  that 
we  have  had  a  chemical  conscience.  We  have 
felt  that  it  is  not  true,  in  spite  of  tradition 
and  public  opinion  and  the  so-called  wisdom 
of  the  ages.  We  resolved  some  day  to  prove 
that  it  was  false,  and  we  have  done  so.  We 
have  made  a  silk  purse  of  a  sow's  ear. 

The  first  question  to  answer  was:  What 
does  the  silkworm  do  —  how  does  it  make 
silk? 

It  eats  mulberry  leaves  and  produces 
threads  by  a  chemical  process  —  by  a  very 
intricate  chemical  process. 

If  we  watch  it  carefully  we  shall  have 
abundant  occasion  to  marvel;  but  science 
teaches  us  that  to  marvel  is  but  the  prelim- 
inary phase  of  observation.  We  cannot  at- 
tain results  by  marveling  alone;  so  closer 
study  reveals  the  fact,  long  known  to  en- 
tomologists, that  the  silkworm  has  in  its 
head  two  very  fine  ducts,  or  openings,  that 
have  a  common  external  orifice. 


PAGE    ONE 

458699 


OK  tks  Making  of 
from  Sows'  Ears 


When  the  time  comes  for  it  to  make  the 
Great  Change,  to  transform  itself  from  a 
gluttonous  worm  into  a  winged  moth,  to 
cease  its  gross  existence  as  a  creeping  thing 
and  to  enter  into  an  aerial  life,  to  sip  honey 
and  to  make  love,  it  requires  an  envelope  for 
hiding,  for  a  dark  and  secret  place,  according 
to  the  command  of  Nature. 

From  certain  glands  at  the  back  of  its 
head  it  ejects  two  minute  threads  of  a  viscous 
liquid  which  become  coated  with  another 
secretion  flowing  from  two  other  convenient 
glands,  and  these  two  little  streams  are  thus 
cemented  to  a  double  strand. 

On  reaching  the  air  the  thread  coagulates 
and  becomes  a  firm,  continuous  filament  of 
silk.  With  this  thread  the  caterpillar  makes 
its  cocoon,  seals  it  up,  and  straightway  goes 
into  its  mystic  lepidopteran  sleep.  When  the 
day  of  awakening  is  at  hand  the  young  moth 
softens  the  end  of  its  cocoon  by  wetting  it 
with  an  alkaline  solution  from  its  head,  and 
so  forces  its  way  out.  Then,  ho,  for  moonlit 
gardens  and  a  short  life  full  of  adventure,  of 
cosmic  urge,  and  of  strange  experiences! 

The  Chinese  say  it  was  a  lovely  and  gifted 
queen  who  was  the  mother  of  the  silk  in- 
dustry, and  industry  —  whether  out  of  the 
mind  of  the  lovely  queen  or  that  of  one  of 
her  followers,  we  do  not  pretend  to  know  — 
has  discovered  that  the  moth  destroys  the 
continuity  of  the  fibre  by  forcing  its  way  out. 
Therefore  industry  foreordains  the  moths  to 
death  before  they  are  born,  if  they  are  to  con- 
tribute silk,  by  steaming  them  or  freezing 
them  or  submitting  them  to  dry  heat. 


PAGE    TWO 


On  the  Making  of  Silk  Purses 
from  Sows'  Ears 


The  cocoon  consists  of  a  loosely  woven 
outer  layer  called  the  "floss,"  which  envelops 
the  inner  part  called  the  "pod,"  which  in  turn 
encloses  the  sleeping,  changing  worm  and 
finally  the  unborn  moth.  About  one  sixth  of 
the  cocoon  is  available  for  fibre,  of  which 
about  one  half  can  be  unwound  and  reeled, 
while  the  remainder,  from  the  floss  and  inner 
pod,  is  combed  or  carded  and  spun. 

Our  particular  interest  was  in  the  silk- 
worm as  a  chemist.  It  emits  a  viscous  liquid 
which,  on  reaching  the  air,  turns  into  a  silk 
thread.  This  viscous  liquid  is  very  like 
glue  —  it  hardens  in  the  air  like  it  and  is 
becousined  to  it,  chemically.  This  chemical 
cousinship  is  an  important  point. 

Again,  the  sow's  ear  being  chiefly  gristle 
and  skin,  we  have  in  it  a  natural  raw  ma- 
terial for  glue.  The  first  step,  then,  was  to 
treat  some  glue  so  that  it  would  behave  as 
much  as  possible  like  the  viscous  liquid 
which  the  silkworm  exudes  as  the  last  deed 
of  its  vermiforous  life.  This  was  done,  and 
after  some  experiments  we  adopted  the 
method  which  we  shall  soon  describe. 

Next  we  wrote  to  Messrs.  Wilson  &  Com- 
pany, of  Chicago,  who,  it  is  needless  to  say, 
had  a  sow.  Indeed  they  had  many  of  them— 
so  many  that  they  cut  off  and  placed  at  our 
disposal  no  less  than  one  hundred  pounds  of 
ears,  with  an  affidavit  that  they  were,  as 
represented,  the  ears  of  departed  sows. 

Being  thus  abundantly  provided  with  the 
raw  material  for  our  silk  purse,  we  prevailed 

imiiiiiiiiimiiiiiiiiiiiiiiiiiimimiiiiiiiiiiiiiiiiiiiiiimiiiiiiiimiiiiiiiiiiiiimiN 

PAGE    THREE 


On  the  Making  of  Silk  Purses 
from  Sows'  Ears 


upon  Messrs.  Wilson  &  Company  to  under- 
take the  extraction  of  glue  from  these  iden- 
tical ears.  This  was  done  in  their  Research 
Laboratory  under  the  personal  and  scientific 


LABORATORIES. 

*"'•'"«»»•  March  18th,  19£1. 


STATE   Of  ILLINOIS)      -c 
COOTTY   Of  COOK        ) 


c^   being  duly  sworn  deposes  and  Bays  that  he  Is  employ- 
ed by  WirSOH  &  COMPAHY,  Inc.,  Chicago,  Illinois  as  Vt  t,  ^-^t^j  V'^^* 
and  that  he  supervised  the;  manufacture  and  packing  of  ten  pounds  of  gela- 
tine shipped  to  Arthur  D.  little,  Inc.,  Cambridge,  llaee.,  on  the  l£th  day 
of  March,  by  parcel  post  (Insurance  Bo.  G  441424)  and  that  said  gelatine 
was  manufactured  wholly  from  sows'  ears. 

And  further  deponeth  and  sayeth  r.ot, 

Signed' 

Subscribed  and  sworn  to 
before  me  this  17th  day 
of  March  -  1  9  £  1 


»** 

,]  Rotary  Publi 


control  of  their  chemist,  Mr.  Frank  R.  John- 
son, to  whom  we  here  take  pleasure  in  making 
our  acknowledgments.  The  glue,  with  Mr. 
Johnson's  identifying  affidavit,  was  for- 
warded to  us  under  seal,  and  we  thereupon 
proceeded  with  our  work  of  transformation. 

Undoubtedly  sows'  ears  lose  somewhat  of 
their  individuality  when  handled  in  one- 
hundred  pound  lots,  —  more  so,  for  in- 


PAGE    FOUR 


On  the  Making  of  Silk  Purses 
from  Sows'  Ears 


stance,  than  persons,  —  but  we  like  to  think 
that  the  particular  portion  of  glue  which 
constitutes  the  silk  from  which  we  made  the 
purse  was  derived  from  the  ear  of  a  particu- 


Itorch  18th,  1921. 


STATE  of  miSOIS) 
COCKTY  of  COOK   j 


being  duly  sworn  deposes  and  Bays  that  he  IB  employed 

Ey  WILSON  &  COMPANY  Inc.,  at  Chicago.  Illinois  BE  O^uc^~  ^^^    and 
that  he  supervised  the  accumulation  of  one  hundred  pounds  (100  Ibs.)  of 
ears  taken  entirely  from  cows. 


And  further  deponeth  and  sayeth  not, 


before  me  this  17th  day 
of  March  -  1  9  E  1 


-       . 

Notary  Public 


larly  estimable  sow  called  "Sukie"  back  on 
the  farm.  To  call  her  "Sukie"  has  been  our 
only  flight  of  fancy  in  this  entire  transaction. 
The  rest  was  straight  laboratory  work. 
Sukie's  picture  is  on  the  frontispiece.  And  now, 
although  Sukie  has  passed  away  after  the  ap- 
proved manner  of  porcine  flesh,  and  has  been 
resolved  into  hams  and  bacon  and  sausage 
and  lard  and  soap,  and  what  is  generally 
known  as  provisions  and  chemicals,  Sukie's 
ear  —  Sukie's  right  ear,  let  us  hope  —  abides 
with  us,  translated  and  glorified  into  a 
beautiful  blue  purse,  a  challenge  to  tradition 
and  a  contradiction  of  the  wisdom  of  the  ages. 

imiiiiiiiiiiiiiiiiiiNiiiiiiiiiiiiiiimiiiiiiiiiiimiiiiiiiiimiiiiiiiiiiHimiiiiiiiiiiiiiimiiiimiiiimimiimiiiiim 

PAGE   FIVE 


On  the  Making  of  Silk  Purses 
from  Sows'  Ears 


While  we  cannot  trace  Sukie's  history 
back  of  her  arrival  in  Chicago,  we  know  how 
she  lost  her  life  and  her  ears,  and  of  the  de- 
velopment of  her  ears  into  glue.  Now  let  us 
tell  what  we  did  with  the  glue  from  the  sows' 
ears  until  it  became  a  silk  purse.  • 

First,  it  was  dispersed  in  water,  then  a 
small  amount  of  acetone  was  added  to  bring 
it  almost  to  a  jelly,  and  a  little  chrome  alum 
helped  to  expedite  its  subsequent  setting. 

The  next  step  was  to  filter  it  very  care- 
fully under  pressure,  after  which  it  was  placed 
in  the  spinning  apparatus.  This  was  an  en- 
closed copper  container  with  one  (long)  pipe 
reaching  nearly  to  the  bottom  and  a  second 
pipe  just  reaching  through  the  cover.  The 
container  was  immersed  in  warm  water  and 
the  short  pipe  connected  with  a  pressure 
cylinder  containing  carbon  dioxide,  —  i.e., 
carbonic  acid  gas.  The  outside  end  of  the 
long  pipe  was  bent  over  like  an  inverted  U 
and  connected  with  the  spinneret,  which  was 
of  metal,  about  the  size  and  shape  of  a  large 
thimble,  and  perforated  at  the  end  with 
sixteen  very  fine  holes  about  1/1000  of  an 
inch  in  diameter.  The  end  of  the  spinneret 
dipped  under  the  surface  of  a  coagulating 
and  hardening  mixture  of  acetone  and 
formaldehyde  contained  in  a  large  V-shaped 
glass  tube  two  inches  in  diameter  with  arms 
about  three  feet  long.  The  arm  of  the  tube 
below  the  spinneret  was  vertical,  the  other 
arm  extending  at  a  slant. 

Then  the  valve  in  the  carbon  dioxide 
pressure  tank  was  turned  on.  That  forced 


PAG E   SIX 


On  the  Making  of  Silk  Purses 
from  Sows' Ears 


the  solution  in  the  copper  container  up 
through  the  long  tube,  down  through  the 
spinneret,  and  into  the  formaldehyde  and 
acetone  mixture  in  the  V  tube.  It  came  out 
as  sixteen  very  fine,  colorless  streams,  so  fine 
as  to  be  hardly  visible,  but  these  filaments  on 
the  way  down  through  the  V  tube  joined  into 
one  composite  fibre  which  was  hardened  by 
the  formaldehyde.  When  it  reached  the 
bottom  it  was  fished  up  with  a  wire  hook, 
drawn  out  of  the  slanting  arm,  and  from  this 
pulled  over  a  rotating  drum  into  a  pan  con- 
taining more  of  the  formaldehyde  and 
acetone  mixture.  At  this  point  the  fibre 
was  very  swollen,  and  had  hardly  any 
strength  at  all.  It  had  to  be  removed 
quickly  and  wound  on  a  reel  to  dry,  else  it 
would  have  become  too  brittle  for  any  use. 

After  the  first  drying  it  was  brittle  and 
without  lustre  —  indeed,  it  was  a  very  un- 
promising thread.  But  by  soaking  for  a  short 
period  in  a  bath  of  forty  per  cent  glycerine,  in 
which  it  was  also  dyed,  and  after  drying 
again,  the  bright  lustre  appeared,  and  it 
developed  the  desired  soft,  silky  feel.  It  was 
then  ready  for  weaving,  which  we  did  on  a 
small  hand  loom,  and  the  fabric  was  finally 
sewed  up  into  the  form  and  substance  of  a 
silk  purse.  The  tassels  are  a  continuation  of 
the  warp  threads,  each  thread  being  a  com- 
posite of  the  sixteen  original  filaments. 

The  purse  is  of  the  sort  which  ladies  of 
great   estate   carried   in   medieval   days  — 
their  gold  coin  in  one  end  and  their  silver 
coin  in  the  other.     It  is  one  of  which  both 
Her  Serene  and  Royal  Highness  the  Queen 


PAGE    SEVEN 


On  the  Making  of  Silk  Purses 
from  Sows'  Ears 


of  the  Burgundians  in  her  palace,  and  the 
lowly  Sukie  in  her  sty,  might  well  have  been 
proud.  When  it  is  not  on  show  at  the  Ex- 
position, its  place  will  be  in  our  chemical 
museum  in  Cambridge. 

We  admit  frankly  that  it  is  not  very 
strong  or  very  good  silk,  and  that  there  is  no 
present  industrial  value  in  making  it  from 
glue.  The  artificial  silk  that  is  made  in 
great  quantity  is  made  from  cellulose,  either 
cotton  or  wood  fibre.  There  is  more  cotton 
and  wood  fibre  available  than  there  are  hoofs 
and  horns  and  ears  of  animals,  and  conse- 
quently of  glue,  and  the  threads  are  stronger. 

We  have  no  intention  of  producing  sow's 
ear  silk  for  the  market.  We  made  this  silk 
purse  from  a  sow's  ear  because  we  wanted 
to,  because  it  might  serve  as  an  example  to 
clients  who  come  to  us  with  their  ambitions 
or  their  troubles,  and  also  as  a  contribution  to 
philosophy. 

The  most  discouraging  thing  to  hear,  if 
you  are  interested  in  real  progress  and  in  the 
forward  march  of  events,  or  more  particu- 
larly if  you  have  set  your  heart  on  doing 
something  that  you  believe  should  be  done, 
is  some  old  saw  that  is  repeated  merely  be- 
cause the  words  that  tell  it  have  been 
learned,  parrot-wise. 

For  thirty-five  years  we  have  been  fight- 
ing such  expressions  as  "What's  the  use?" 
"It  isn't  done,"  "It  isn't  practical,"  "We've 
got  no  time  for  theories,"  and  all  the  other 
wretched  substitutes  for  hard,  earnest, 
straight  thinking. 

I    '    !     ii  ill:'l:  !!•  !'    'I    'I  ,!l  ^'.ill'M'.!!.!:  ll,:.!.!!!  II!  ill    li:  I    ir    II    V  'I!  M!  -INLII-II,    II'  ll:ll:!:ll    Hi  l|;!|l  M:  :':  II!  i|.    II;    i; 

PAGE    EIGHT 


On  the  Making  of  Silk  Purses 
from  Sows'  Ears 


Things  that  everybody  thinks  he  knows 
only  because  he  has  learned  the  words  that 
say  it,  are  poisons  to  progress.  The  only  way 
to  get  ahead  is  to  dig  in,  to  study,  to  find  out, 
to  reason  out  theories,  to  test  them  —  and 
then  to  hold  fast  to  that  which  is  good. 


This  making  of  silk  purses  of  sows'  ears 
was  merely  a  diversion  of  chemistry  at  play. 
When  chemistry  puts  on  overalls  and  gets 
down  to  business,  things  begin  to  happen 
that  are  of  importance  to  industry  and  to 
commerce.  New  values  appear.  New  and 
better  paths  are  opened  to  reach  the  goals 
desired. 


PAGE    NINE 


PPHPI 


EARNSHAW     PRESS     CORPORATION.    BOSTON 


Syracuse,  N.  V 

PAT.  JAN.  21.  1908 


458699 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 


